This research investigates how an inferior search engine can impact its competition with a superior search engine by introducing a knowledge-sharing service. Specifically, we model the dynamic competition between an inferior search engine with a knowledge-sharing service and a pure superior search engine. We show that the degree to which the knowledge-sharing service helps the inferior search engine to enlarge its market share increases as the amount of online content decreases and the complexity of searchers' questions increases. We also find that the inferior search engine is generally advised to close its database of answers for more market share